One main portal site one eshop on same server

Hello everybody,
I’m pretty sure this have already been discussed before but I don’t find exactly what I need.
So I have my main portal website placed in a ‘WordPress” folder. With a .htaccess and index.php in the root of the hosting pointing to it, it runs fine.
I’d like to add another website on this server (an e-shop version of the portal), I’ve created a folder called ‘eshop’ at the root level next to the ‘wordpress’ folder. I’ve installed the new wordpress site in it, admin and homepage work fine but when I try to dig into the ehop, it brings me to the 404 of the portal.
I’d like to set the permalinks of the eshop to ‘post-name’, but WordPress Admin ask me to change the .htaccess in order to validate it. And here is my second problem : how to set my htaccess to make both sites working?
for now, my htaccess command is this :

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

and I should add this for the eshop :

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /eshop/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /eshop/index.php [L]
</IfModule>